What is not a polymer?
Starch
What is the chemical mechanism by which cells make polymers from monomers?
Dehydration reactions
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
10
What best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking 3 glucose molecules together by dehydration reactions?
C18H30O15.
A molecule with the chemical formula C6H12O6 is probably a....
Monosaccharide.
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
As a disaccharide.
Which is not a polysaccharide?
Glucose.
What is true about both starch and cellulose?
They are both polymers of glucose.
What is true about cellulose?
It is a major structural component of plant cell walls.
What is NOT true about saturated fats?
They have multiple double bonds in the carbon chains of their fatty acids.
A molecule with the formula C18H36O2 is probably a....
Fatty acid.
What is NOT true about the class of biological molecules known as lipids?
They are soluble in water.
What is a triacylglycerol?
A lipid made with three fatty acids and glycerol.
What is true about saturated fatty acids?
They are the principal molecules in lard and butter.
Large organic molecules are usually assembled by a polymerization of a few kinds of simple subunits. What is an exception to this statement?
A steroid.
The hydrogenation of vegetable oil results in which of the following?
Saturated fats and unsaturated fats with trans double bonds, an increased contribution to artherosclerosis, and the oil (fat) being a solid at room temperature.
Why are human sex hormones considered to be lipids?
They are steroids, which are not soluble in water.
What does not contain any amino acids?
Enzymes.
The bonding of two amino acid molecules to form a larger molecule requires....
the release of a carbon dioxide molecule.
There are 20 different amino acids. What makes one amino acid different from the other?
Different amino groups attached to an alpha carbon.
The bonding of 2 amino acid molecules to form a larger molecule requires what?
Removal of a water molecule.
Polysaccharides, lipids, and proteins are similar in that they....
are synthesized by dehydration reactions.
Dehydration reactions are used in forming what compounds?
Tricylglycerides, polysaccharides, and proteins.
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?
99
How many different kinds of polypeptides, each composed of 12 amino acids, could b synthesized using the 20 common amino acids?
20^12
What bonds are created during the formation of the primary structure of a protein?
Peptide bonds, hydrogen bonds, and disulfide bonds.
What maintains the secondary structure of a protein?
Hydrogen bonds.
What type of interaction stabilizes rhe alpha helix and the beta pleated sheet structures of proteins?
Hydrogen bonds.
The alpha helix and the beta pleated sheet are both common polypeptides forms found in which level of proteins structure?
Secondary.
The tertiary structure of a protein is the....
unique 3D shape of the fully folded polypeptide.
A strong covalent bond between amino acids that functions in maintaining a polypeptide's specific 3D shape is a....
disulfide bond.
At what level of protein structure are interactions between the side chains (R groups) most important?
Primary, secondary, tertiary, and quaternary.
The R group or side chain of the amino acid serine is -CH2 -OH. The R group or side chain of the amino acid alanine is -CH3. Where would you expect to find these amino acids in a globular protein in aqueous solution?
Serine would be in the interior, and alanine would be on the exterior of the globular protein.
What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 acids?
The primary structure of the protein would be changed, the tertiary structure of the protein might be changed, and the biological activity or function of the protein might be altered.
Altering what level of structural organization could change the function of a protein?
Primary, secondary, tertiary, and quaternary.
The function of each protein is a consequence of its specific shape. What is the term used for a change in a protein's 3D shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds?
Denaturation.
What is the term used for a protein molecule that assists in the proper folding of other proteins?
Chaperonin.
DNAse is an enyzme that catalyzes the hydrolysis of the covalent bonds that joins nucleotides together. What would first happen to DNA molecules treated is DNAase?
All bases would be separated from the deoxyribose sugars.
The main pruose of RNA is to....
function in the synthesis of protein.
What best describes the flow of information in eukaryotic cells?
DNA to RNA to Proteins
What best describes the class of molecules known as nucleotides?
A nitrogenous base, a phosphate group, and a pentose sugar.
What are nitrogenous bases of the pyrimidine type?
Cytosine and uracil.
What are nitrogenous bases of the purine type?
Guanine and adenine.
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
COME BAck to
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA....
contains one less oxygen atom.
What best summarizes the structural differences between DNA and RNA?
DNA nucleotides contain a different sugar than RNA nucleotides.
In the double helix structure of nucleicacids, cytosine hydrogen bonds to....
guanine.
If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence....
3'TAACGT5'.
A new organism is discovered in the forests of Costa Rica. Scientists there determined that the polypeptide sequence of hemoglobin from the new organism has 72 amino acids differences from humans, 65 differences from a gibbon, 49 differences from a rat. and 5 differences from a frog. This data suggests that the new organism....
is more closely related to frogs than to humans.
The element nitrogen is present in all of the following except....
monosaccharides.
What is a diverse group of hydrophobic molecules?
Lipids.
What stores and transmits hereditary information?
Nucleic acids.
Enzymes are....
proteins.
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking 10 glucose molecules together by dehydration reactions?
C60H102O51
The structural level of a protein least affected by a disruption in hydrogen bonding is the....
primary level.